In recent years, a graphical user interface (GUI) allows for animation display, as the processing performance of a computer is improved, and a web browser function using a script language is improved. Therefore, generally, recently available web browsers are internally provided with an animation drawing function of animation-displaying a GUI.
Such a web browser sequentially executes script data described in an interpreter script language for animation-displaying a GUI. For instance, patent literature 1 discloses a technology of executing script data for animation-displaying a GUI. FIG. 15 is a block diagram showing a general configuration of a conventional animation drawing device 70 for animation-displaying a GUI by executing script data, as disclosed in patent literature 1.
The animation drawing device 70 shown in FIG. 15 is provided with a script data storage 701, an interpreter 702, a graphics drawing controller 703, and a graphics processor 704. A display device 71 is a device for displaying an animation to be drawn by the animation drawing device 70. The script data storage 701 stores script data for animation-displaying a GUI. In this example, the script data is data described in an interpreter script language, and is described in e.g. the JavaScript (trademark).
The script data describes data for defining attribute information of GUI objects constituting a GUI for animation, and animation drawing instructions for animation-displaying the GUI.
The attribute information is data for defining various parameters such as the coordinate, the size, the enlargement/reduction ratio, the rotation rate (roll angle, pitch angle, yaw angle), the color, the transmittance, and the image of a GUI object to be displayed. For instance, in the case where an animation of linearly moving a GUI object on the screen of the display device 71 is implemented, there is described, in the script data, a loop processing of setting a coordinate representing a start point and a coordinate representing an end point as variables, and moving the GUI object little by little by changing the variables little by little.
The interpreter 702 sequentially interprets the script data, and outputs a graphics drawing instruction to the graphics drawing controller 703, each time the script data is interpreted.
The graphics drawing controller 703 breaks down the graphics drawing instruction sent from the interpreter 702 into low-level drawing commands executable by the graphics processor 704, and outputs the drawing commands to the graphics processor 704. The graphics drawing controller 703 is constituted of a software, and is generally called as a graphics library or a device driver.
The graphics processor 704 executes a drawing command outputted from the graphics drawing controller 703, and generates a graphics by drawing a frame in a built-in frame buffer. The graphics processor 704 is constituted of a hardware such as a graphics processing unit (GPU).
FIG. 16 is a diagram conceptually showing a structure of script data 701a to be described in the case where the conventional animation drawing device 70 is used. FIG. 16 shows that the script data 701a includes an animation control program 7011 described for animation-displaying a GUI.
Since the animation control program 7011 is described in an interpreter script language, the interpreter 702 is required to frequently execute a retrieval processing. The retrieval processing obstructs an increase in the execution speed of the animation drawing device 70 in animation-displaying the GUI.
There is known, as an approach of increasing the execution speed in animation-displaying a GUI, an approach of replacing the animation processing described in the script language with a native program described in a native language. In this approach, the script data 701a calls out an API of the native program via the interpreter 702 to cause the API to execute the animation processing. As is well known in the art, a program described in a native language requires a short processing time, as compared with a program described in a script language. Accordingly, the above replacement approach allows for increasing the execution speed of animation.
However, in the conventional approach, the program described in a native language is required to perform an animation processing including a step of acquiring variables from the interpreter 702. Consequently, the interpreter 702 is required to perform a variable retrieval processing in acquiring the variables, which may lower the execution speed of the GUI.